NEW YORK (NYTIMES) The Federal Bureau of Investigation (FBI) has arrested an American woman whom federal prosecutors said had risen through the ranks of the Islamic State in Iraq and Syria (ISIS) group to become a battalion commander, training women and children in Syria to use assault rifles and suicide belts, the Justice Department disclosed Saturday (Jan 30).

The woman, Allison Fluke-Ekren, 42, a former teacher from Kansas, was charged with providing material support to a terrorist organisation.

The circumstances of her capture in Syria were not immediately known, but the FBI flew her to Virginia on Friday to face prosecution.

Prosecutors described Fluke-Ekren as playing an unusually outsized role in ISIS as a woman and an American.

Charges against American women involved with the militant group have been rare.

Fluke-Ekren was smuggled into Syria in 2012 from Libya, court documents said.

She travelled to the country, according to one witness, because she wanted to wage "violent jihad", federal prosecutor Raj Parekh wrote in a detention memo that was made public Saturday.

According to a criminal complaint that was filed in 2019, a witness told the FBI that Fluke-Ekren and her husband brought US$15,000 (S$20,300) to Syria and used the money to buy weapons.

Her husband, the witness said, was the commander of snipers for ISIS; he later was killed by an airstrike while trying to conduct a terrorist attack, investigators said.

Fluke-Ekren had met him in the US, according to court documents.

The same witness also told the FBI that Fluke-Ekren had a plan in 2014 to attack a college in the US using a backpack filled with explosives.

Prosecutors did not reveal which college she had wanted to target.

The criminal complaint said her plan was presented to Abu Bakr al-Baghdadi, the leader of ISIS at the time, who approved funding for it.

The witness said the attack was put on hold after Fluke-Ekren learned she was pregnant. Fluke-Ekren had multiple children, but it is not clear how many.

Prosecutors said Fluke-Ekren moved to Egypt in 2008, lived there for about three years and then travelled to Libya, where she stayed for about a year before sneaking into Syria.

According to one witness, Fluke-Ekren departed Libya because another terrorist organisation, Ansar al-Sharia, was no longer conducting attacks in that country and she wanted to wage violent jihad.

In his memo arguing to keep Fluke-Ekren behind bars while she awaits trial, Mr Parekh said she had been a "fervent believer in the radical terrorist ideology of ISIS for many years".

The prosecutor said the government had numerous witnesses who were prepared to testify against her.

According to the detention memo, the mayor of the Syrian city of Raqqa, ISIS' self-proclaimed capital, approved the opening of an all-female military battalion. Fluke-Ekren, investigators said, soon became the leader and organiser of it.

Witnesses said Fluke-Ekren taught classes for members of the battalion, and on one occasion, a young child of hers was seen holding a machine gun. More than 100 women and girls received training from her, one witness said.

Fluke-Ekren had hoped to create a cadre of suicide bombers that could infiltrate enemies' positions, but the effort never materialised, according to the complaint.

She also told a witness about her desire to attack a shopping mall using a remote-detonated vehicle full of explosives.

Court documents said that after the death of her husband, Fluke-Ekren married another ISIS terrorist, a Bangladeshi man who specialised in drones and worked on a plan to drop chemical bombs using them.

He also died. She then married an ISIS military leader who was responsible for the defence of Raqqa, a witness said.

A witness also said that Fluke-Ekren claimed to have tried to send a message to her family with the goal of tricking them into believing she was dead so the US government would not try to find her.

She told the witness that she never wanted to go back to the US and wanted to die a martyr in Syria.